JPS5931704Y2 - Galvanic anode cathodic protection equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a galvanic anodic cathodic protection device that is underwater welded to a steel material to be protected under water when performing cathodic protection on the underwater steel material.

Conventionally, the method for attaching galvanic anodes for corrosion prevention to underwater steel materials such as in port facilities is the hanging method, which involves welding the core of the anode to the tip of the metal fitting. The main method of attaching the anode by hanging it underwater along the object to be protected was by welding the upper end of the metal fitting to the steel material of the object to be protected. Due to the repeated pendulum motion, there are many accidents in which the anode attachment near the fixed part of the metal fitting suffers fatigue due to repeated bending stress and breaks. It is gradually no longer used because it is difficult to use both economically and in terms of construction technology, such as the need for metal fittings.In recent years, it has been replaced with synthetic resin paint or covered with synthetic resin tape. A method called wet underwater welding, in which a waterproof welding rod is used to generate an arc between the workpiece and the workpiece directly underwater, is used to fix the anode to the steel material to be protected against corrosion. ing.

The method of attaching the anode by wet underwater welding is that the anode can be fixed underwater by welding using the same simple method as on land, so the anode can be easily attached to any position on the steel material to be protected by welding. This is an advantageous method from the viewpoint of the distribution of anti-corrosion current.

However, with wet underwater welding, welding is performed by directly generating an arc underwater, so the weld metal and weld heat-affected zone are rapidly cooled by water, making it impossible to produce high-quality welds, and the strength is inferior to land-based welding. There is a drawback.

In recent years, due to the increase in the size of steel materials to be protected against corrosion underwater and the emphasis on safety, there has been an increase in the use of long-life anodes, and due to the increase in the size of anodes, it is desirable to improve the quality of the welded part for underwater welding when attaching anodes. It is rare.

In view of the above-mentioned current situation, the present invention provides a galvanic anode type cathodic protection device which uses a dry underwater welding method in water and has a high quality and stable welded part.

Examples will be described below with reference to the drawings.

FIG. 1 is a schematic explanatory diagram of underwater welding in the apparatus of the present invention.

FIG. 2 is a diagram showing the state in which the galvanic anode 1 is mounted vertically on the steel material 12 to be protected against corrosion in the apparatus of the present invention, and FIG. 3 is a diagram showing the state in which it is mounted horizontally.

In the device of the present invention shown in FIG. 2, a groove-shaped galvanic anode with two open sides contacting core metals 2a protruding from both ends of a galvanic anode 1 made of aluminum alloy, etc. is mounted on one of the metal fittings 3a. The mounting is performed so that the metal fitting 3 is welded on land 4 so that the open surface is in the same direction with respect to the cross section of the mandrel 2a, and the other open surface is in the same direction with respect to the longitudinal section of the mandrel 2a. The anode body attached by is brought into contact with the surface of the steel material to be protected 12 soaked in water so that the above-mentioned open faces overlap and the above-mentioned one open face faces downward; The attachment is carried out by underwater welding 6 on the contact surface between the inner side of the end surface 5 of the metal fitting 3a and the steel material 12 to be protected against corrosion.

For mounting the anode, metal fittings having various shapes can be used, such as those shown in FIGS. 6 and 7, in addition to the shapes shown in the perspective view of FIG. 4 and the sectional view of FIG. 5.

The construction method of the device of the present invention will be explained below based on the drawings.

In Figures 1 to 3, the core 2a of the anode 1 and the metal fittings 3a are connected to both ends of the anode core by welding on land as shown in the figure in advance, and the anode is transported to the location for underwater anode installation. The anode is attached by wet underwater welding so that the end face 5 of the leg of the metal fitting is in contact with the surface of the steel material 12 to be protected.The anode is attached by temporarily welding the outer end of the metal fitting to the steel material 12 to be protected. put.

Next, when the magnet 8 is used to blow out gas from the gas hose 7 attached to the anode fitting, the water inside the anode fitting is expelled and the water surface drops to the bottom of the anode fitting. The interior of the metal fitting is hollow, and the contact portion between the anode mounting metal fitting and the steel material to be protected is arc welded in the cavity until sufficient strength is obtained.

The other end of the gas hose 7 is connected to an air compressor or gas cylinder (not shown), so that high-pressure gas can be sent through the gas hose.

By the above method, the upper and lower anodes are attached by welding the metal fittings, thereby firmly fixing the anode to the steel material to be protected.

After the installation of the anode is completed, the hose 7 is removed, the next anode installation is carried out to a location, and the anode can be installed in the same manner.

Further, the gas used for forming the underwater welding cavity according to the present invention may be a shielding gas such as carbon dioxide gas or argon gas, but air may also be used.

As explained above, with the device of the present invention, welds of much higher quality and more stable than conventional methods can be obtained, and the attachment between the anti-corrosion galvanic anode and the steel material to be protected in water can be maintained securely and firmly. reliability can be improved.

[Brief explanation of the drawing]

Figure 1 is a schematic explanatory diagram of underwater welding using the device of the present invention, Figure 2 is a state diagram of the device of the present invention when the anode is attached vertically to the steel material to be protected, and Figure 3 is a diagram of the device of the present invention with the anode Fig. 4 is a diagram showing the shape of the metal fittings for groove-shaped anode installation, Fig. 5 is a cross-sectional view of the metal fittings for groove-type anode installation, and Fig. Figure 6 is a cross-sectional view of the trapezoidal anode installation and metal fitting installation, and Figure 7 is a cross-sectional view of the round steel core bar and chevron-shaped anode installation. 1...Anode, 2a...Flat steel core, 2b
......Round steel core, 3a...Metal fittings for grooved anode installation, 3b...Metal fittings for trapezoidal anode installation, 3
C: Mounting the chevron anode using metal fittings, 4...
Land welding part, 5... End face, 6... Underwater welding part, 7... Hose, 8... Magnet,
9... Welding holder 10... Welding rod,
11... Cabtire cable, 12...
... Steel material to be protected against corrosion.

Claims (1)

[Scope of utility model registration request] Two box-shaped mountings with two open faces are welded to the metal fittings protruding from both ends of the galvanic anode so that the two sides of the metal fittings are in the same direction. The body is placed in an electrolyte solution so that one side of the metal fitting faces downward and the other side overlaps the surface of the steel material to be protected, and the contact portion between the metal fitting and the steel material inside the metal fitting is dry underwater welded. A galvanic anode cathodic protection device characterized by: